A dry pipe sprinkler system or preaction system comprises a fire suppression system that is typically used in structures and areas that are oftentimes unheated and subject to freezing temperatures. The dry pipe sprinkler system includes a network of pipes including branch lines servicing sprinkler heads, risers, and feed mains for delivering water from a water supply to the branch lines. Under normal conditions, this network of pipes contains a pressurized gas, such as air or nitrogen, which holds closed a dry pipe valve that connects the main supply pipes of main feeds of the sprinkler system to the water supply. When heat from a fire opens a sprinkler, the compressed gas is released from the system. The resulting drop in pressure causes the dry pipe valve to open, or trip, thereby releasing water into the main supply lines or main feeds.
When the network of pipes is filled with the pressurized gas and the ambient temperature lowers, condensate can collect in the network of pipes. If the condensate builds up in the system, then there is a risk that the condensate will freeze in the pipes. Freezing condensate can cause pipes to leak or burst, or inhibit the flow of water through the branch lines in the event of fire. For this reason, dry pipe systems often include one or more condensate collector arrangements (sometimes called “drum drips”) which collect condensate from the network of pipes. These drum drips are typically located at low points of the dry pipe system and usually include a drainage valve and a shut-off valve connecting the drum drip to a riser. A drum drip is drained of condensate by first closing the upper valve. This prevents pressurized gas from exiting the system when the drum drip is being drained. The drain valve is then opened and condensate is drained from the drum drip. Then the drain valve is closed again and the upper valve may be reopened to again allow condensate to be collected.
In the conventional condensate collector arrangements, the valve located upstream of the collected condensate is operated independently of the valve that is located downstream of the collected condensate. Accordingly, although the upstream valve should be closed before the downstream valve is opened to drain the collected condensate, it is possible in the conventional arrangements, whether inadvertently or not, for both the upstream valve and the downstream valve to be open at the same time. If this occurs, the dry pipe system may likely lose pressure and trip the fire protection system. Tripping the fire protection system would then likely fill the sprinkler system with water and may also trigger a false alarm indicative of a fire.
NFPA 13 and NFPA 25 requirements concern drainage of dry and preaction sprinkler systems and note that the upper valve is to be closed before the lower valve is opened when the system is charged. However, the valves may still be operated improperly with both valves open at the same time either accidentally or maliciously or due to tampering to trip the system.
Accordingly, the need exists for an arrangement which prevents the upstream valve and the downstream valve in a condensate collector from being fully open at the same time.
The need also exists for a condensate collector with an arrangement to physically prevent the upstream valve and the downstream valve from being fully open at the same time and to prevent the lower valve from being opened by an unauthorized individual.
When the condensate collector is provided in an environment that is subject to freezing temperatures, a need also exists for a condensate collector that indicates the presence of even a relatively small amount of condensate in the condensate collector and in which an alarm that indicates the presence of condensate may be selectively deactivated.